OK, finally got an opportunity to try and address this problem. I followed to the letter the post that showed a 20+ step process that was said to be used by Ford itself to clear the air in the power steering system. Lifted the front end up and turned the wheels lock to lock ten times with the motor off. Checked the fluid and then another 10 lock to lock. Disconnected the ignition and cranked the motor- did another 10 etc.....

No noise with the engine running and steering lock to lock with the front end lifted - we are happy . Put the truck back on the ground and do the final 10 lock to lock and its noisy as before. Take for a test drive and no change - still the same annoying noise. We are mad

Then we try JoWilkers trick with the Lucas Stop Leak and its stills makes noise. And here is another odd thing. The fluid in the reservior is all full of fine froth after we check right after parking. This happened before we added the stop leak by the way. Is this normal? Seems odd. Would it suggest we have an air leak somewhere in the system? No fluid is being lost - not one drop. Where to go next??

 

I just wanted to bring this thread to a close. We finally solved the problem. When I last posted we still had noise and the fluid was full of froth after a drive. This culminated in a short drive one day that ended when I heard a "pissh" in the engine bay and immediately lost my power steering. Stopped and looked and their was power fluid steering all over the engine bay and pouring onto the ground. I didn't have time to do a thorough inspection at the time - just muscled the truck home about as quickly as I could (about a mile from home). I figured it was the pump itself but I felt around and there was nothing obviously wrong on the outside of the pump. I checked the hydralic lines and those were fine. I checked the non-pressurized return and feed lines and found a rupture in the return line from the steering box. This is where the fluid had exploded from.

I figured the pump was toast after having driven the truck about a mile with essentially no fluid so I removed the less than one month old pump and returned to Napa. They were great and gave me a free replacement. We replaced both return and feed lines with new 3/8" tubing and even installed a PS pump filter. Reinstalled the new pump and then flushed the system (before installing the filter). Added fluid and went through the 20 step process noted above. The system is as quiet as a Ford PS pump can ever be - PROBLEM SOLVED.

We surmise that the return line that had ruptured must have had a small leak all along and most likely caused air to get into the original pump making it noisy and causing us to replace it with a new pump. Add to this that this bad return line from the box was somewhat distended and its likely that it was collapsing and starving the pump for fluid and hastening its demise. The first replacement pump was noisy but not near as bad as the original. It was getting noisier right before the line burst. It was likely that it was getting starved as well and air was getting into the system to make things worse.

So in the end, replacing the return line did the trick. Let's hope this "new" rebuilt pump lasts a while. Thanks to all the posters here lending their ideas. In retrospect, we badly misdiagnosed the problem solely as a bad pump when it was really a bad return line leading to a bad pump.

Tomorrow we tackle replacing the HEI distributor - thats what the PO installed and it seems to be working very well. The bearings are shot and you can wiggle the shaft pretty easily. This should be a simple repair, but seems nothing on this truck has been neither straightforward nor simple